A common activity, given the increasing availability of computer-accessible content, is to generate indexed databases of such content and to provide keyword-based search facilities for accessing the information.
For example, a large percentage of the pages, on the World-Wide Web, have been made keyword searchable by search engines. An example search engine is GOOGLE, of Mountain View, Calif., U.S.A.
Keyword search is most effective when records, that are likely to be of interest to the user, can be located with terms that are highly specific to the topic of interest. In many instances, however, highly specific keyword terms can only partly describe the topic of interest. The problems resulting from this inability of keywords, to more fully describe certain search topics, can be twofold. First, a set of records can be returned that is too large for the user to review in a reasonable amount of time. Second, the set of records returned can include many records that are off-topic.
GOOGLE attempts to address the limitations of keywords by ranking the records (more specifically, the web pages) returned according to a “popularity” metric. According to GOOGLE, the popularity of a web page is proportional to the number of other web pages that point to it.
However, for many types of search topics, popularity is not an acceptable proxy for the portion of the topic that could not be adequately expressed with keywords.
An example search topic, where popularity is not an acceptable proxy, is the search for new uses of an existing technology “ET1.” To address this search topic, one would like to search the entire Internet for those web pages where problems (or market needs), that technology “ET1” can be effective at addressing, are discussed. The authors of such pages are likely to be interested in using technology “ET1.” Unfortunately, it is difficult to express, with keywords, the requirement that a web page express or utilize the concept of “problem” or “market need.”
Another example search topic, where popularity is not an acceptable proxy, is the search for an existing technology that can address a problem “P1.” To address this search topic, one would like to search the entire Internet for those web pages where claims of success, at addressing “P1,” are discussed. The authors of such pages are likely to be knowledgeable about an existing technology that can address “P1.” Unfortunately, it is difficult to express, with keywords, the requirement that a web page express or utilize the concept of “claim of success.”
It would therefore be desirable to be able to retrieve records not only on the basis of keywords, but also on the basis of whether a record addresses a concept.